const book = {};
book.author = 'yangjh'
book.pages  = 512
book.title = '前端开发教程';

const person = {
    'name': 'yangjh',
    'age' : 18,
    'weight':120,
    'height':120,
    say: function(message) {
        
    }
};

console.log(person.age)